Friends,Here i am going to tell about 2 of the best OS for gaming

1.Windows 7 ultimate.
2.Windows 7 home premium.

These both OS are best for hard-core gaming,As both of these delivers powerful HD (DIRECTX 11),

Windows 7 ultimate: This edition of windows 7 has all the features of the windows 7 series from starter - professional,And is the most powerful edition among them.So it should be a better option.

Windows 7 home premium: It is made for basic home needs & multimedia support,It is a good platform for average budget gamers

WARNING : DO NOT EVER TRY TO ADD ADDITIONAL SOFTWARE SUPPORT SUCH AS - GAME BOOSTER,TWEAKER,MOODED VERSIONS OF WINDOWS.